<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Document</title>
  <style type="text/css">
    *{
      padding: 0px;
      margin: 0px;
    }
    /*容器的宽度高度充满全屏*/
    html,body{
      width: 100%;
      height: 100%;
    }
    body{
      background-color: pink;
      display: flex;
      flex-direction: row;
      align-items: center;
      justify-content: center;
    }
    .heart{
      width: 200px;
      height: 200px;
      background-color: red;
      position: relative;
      transform: rotate(45deg);
      animation: heartbit 1s alternate infinite;
      box-shadow: 0 0 30px red;
    }
    .heart::after{
      content: '';
      width:200px;
      height: 100px;
      background-color: red;
      border-radius: 100px 100px 0 0;
      position: absolute;
      top:-99px;
      left:0px;
      box-shadow: 0 0 30px red;
    }
    .heart::before{
      content: '';
      width:100px;
      height: 200px;
      background-color: red;
      border-radius: 100px 0px 0px 100px;
      position: absolute;
      left:-99px;
      top:0px;
      box-shadow: 0 0 30px red;
    }

    @keyframes heartbit{
        0%{
          transform: rotate(45deg) scale(0.6);
        };
        100%{
          transform: rotate(45deg) scale(1.3);
        }

    }
    .speak{
      display: inline-block;
      height:30px;
      line-height: 30px;
      font-size: 30px;
      color: palevioletred;
      position: absolute;
      margin-top: 320px;
      box-shadow: 1px 1px 30px palevioletred;
      padding: 4px;
    }
  </style>
</head>
<body>
  <div class="heart"></div>
  <i class="speak">I love you</i>
</body>
</html>